1. Field of the Invention
The present invention relates generally to apparatuses for program execution operating based program information read from a floppy disc or the like and methods for such program execution, and more specifically, to an image reproduction apparatus which reproduces a still picture for display and performs image effects such as wipe and dissolve at the time of switching images.
2. Description of the Background Art
Image reproduction apparatuses which sequentially display a plurality of still pictures have been used. Such an image reproduction apparatus is used for automatic exhibition of still pictures, for example, at museums, art museums or show rooms.
As one example of such an image reproduction apparatus, there is disclosed an image file apparatus in Japanese Patent Laying-Open No. 3-30176. The image file apparatus reproduces and displays image data based on control by execution of program information, and switches images by means of image effects such as scroll and wipe.
Since in an image reproduction apparatus, program information thus controls the automatic exhibition operation of the image reproduction apparatus, changing program information read into the image reproduction apparatus can readily change the automatic exhibition operation. This applies to any computer equipment which operates based on read program information besides such an image reproduction apparatus.
In such an image reproduction apparatus, when an improvement (producing an upper version) such as providing apparatus with an additional new function which has not been known before, a new program code (hereinafter referred to new code) corresponding to the improvement is set.
More specifically, a new code for a special image effect which can be achieved only with the improved version of image reproduction apparatus is additionally provided. In the improved image reproduction apparatus capable of interpreting thus added new code, when program information with the new code is executed, images can be switched by means of a special image effect.
If such program information written with the new code is executed with an old type image reproduction apparatus before the improvement, the inability of the old type image reproduction apparatus to interpret the new code causes errors or stops operation.
Accordingly, new program information described with a new code which cannot be used by the old type image reproduction apparatus cannot be used in common between the improved image reproduction apparatus and the old image reproduction apparatus.
However, use of a comment statement which will be described later enables a method of producing program information which can be used in common between the improved apparatus and the old apparatus.
Program information called "program" is generally formed of a program code statement and a comment statement. The program code statement is an instruction statement for actually operating computer equipment. The comment statement is a statement inserted to aid the producer of the program information in understanding the program code statement, irrespective of the actual operation of the computer equipment.
The computer equipment therefore ignores the comment statement in the program information, extracts the program code statement and executes an operation based on the instruction of the extracted program code statement.
As a specific example, Japanese Patent Laying-Open No. 4-216131 discloses a method of providing a program code statement with a mark designating a comment statement, thereby disabling the program code statement provided with the mark, and the technique is generally known.
The present inventors have contemplated combining a program for an improved image reproduction apparatus (hereinafter referred to as improved type program information) with program information for an old type image reproduction apparatus (hereinafter referred to as old type program), and producing program information in common including one of these pieces of program information as a comment statement. More specifically, this common program information is provided with a mark for comment statement at a portion of the old type program information when it is used at the improved type image reproduction apparatus, while the mark for comment statement is provided at a portion of the improved type program information when it is used at the old type image reproduction apparatus.
Such common program information can therefore operate in either at the improved type image reproduction apparatus or at the old type image reproduction apparatus by replacing the mark for comment statement.
If such common program information is used both at the improved type image reproduction apparatus and at the old type image reproduction apparatus, however, cumbersome replacement of the mark for comment statement was necessary.
A specific example of an image reproduction apparatus utilizing the above-described program information will be described.
A conventional image reproduction apparatus prestores a number of still pictures (A, B, . . . ). In the image reproduction apparatus, when the image is switched from still picture A to still picture B, for example, the image switching is conducted by means of an image effect such as wipe, roll, and dissolve by sequentially changing the combining ratio of still picture A and still picture B.
When "dissolve" is executed, the following control is made. When execution of the image effect "dissolve" is designated with the combining ratio of the image data a of still picture A and the image data b of still picture B being 1:0 (with still picture A being displayed), the density of image data a is reduced as the density of image data b is increased. Thus, still picture data in which image data a and image data b are mixed is formed. In this case, a still picture having still picture A and still picture B mixed therein is displayed as an image.
Finally, the combining ratio of image data a and image data b becomes 0:1 at which point the image effect "dissolve" is terminated and the displayed image is completely switched from still picture A to still picture B.
Generally in such an image reproduction apparatus one image effect is carried out first and another image effect is not carried out until the first image effect is completed. Since such an image reproduction apparatus can carry out only predetermined kinds of image effects, a special image effect cannot be achieved, and only somewhat commonplace image effect is obtained. In addition, if a special image effect e.g. executing an image effect during execution of another image effect is intended, hardware must be changed in order to execute these image effects in parallel. This therefore pushes up cost for implementing such a special image effect.